Copolymers of 2-vinyldibenzofuran and their preparation



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, I t 2,821,223 a coronmans or z-vmrmmanzoruasu' am) 'rnam PREPARATION Edward A, Kern, Pittsfleld, assignor' to 1 General Electric ,Company, acorporation of a NcwYork No Drawing. Application December 11, 1944, Serial No. 567,787

T 1: Claims. (01.280-803) UNITED STATES PATENT omen The present invention relates broadly to coother monomer or monomers employed, it will go polymers of vinylcompounds and their preparapractically to completion before the other mom tion. More specifically, the invention is directed mer or monomers have polymerized or copolyto the preparation ofcopolymers of 2-vinyldime'ri'zed. This may lead to the formation at benzoturan and a difl'erent organic compound 5 mixed polymerization masses instead o! cocontainingat least one polymerizable CH2=C polymers. I grouping. t The copolymerization may be accelerated by Vinyl-substituted dibenzoiurans, such as 2- the use of small amounts of such compounds as vinyldibenzofuran, and the preparation 01' such the organic or inorganic oxides, oxygen-produccompounds are described'and claimed in the coing compounds, air, oxygen, ozone, boron tripending application of. Abbott, Serial No. 567,784, fluoride, tin tetrachloride, antimony pentachlofiled concurrently herewith, now Patent Number ride, acids such as hydrochloric and acid-acting 2,498,473, and assigned to the assignee of the compounds, halogens, hydrohalogens. substances present invention. This invention is directed to 7 having a large surface area such as carbon black, the production or copolymers of 2-vinyldibenzol5 finely divided earths. metallic powders. silex, etc., iuran bythe simultaneous polymerization of this which act as rate accelerato compound and other organic polymerizable com- Various proportions of 2-vinyldibenzoiuran pounds containing at least one polymerizable and .the com-pounds copolymerizable therewith,

CH==C grouping, examples of which are vinyl may be used, a variation in proportions producing compounds; acrylic acid; acrylic acid esters; a variation in the properties of the. final copolyacrylic acid nitrile; dienes, such as isoprene, butamer and the proportions employed being suited diene, etc.; diviuyl compounds such as diviuyl to the nature of the final product desired. For benzene, diviuyl dibenzoi'uran, etc.; diallyl' comexample. 2-vinyldibenzoiuran polymerizes in all pounds; etc. Illustrative examples of other p p s w Styrene to P c c polymers polymerizable organic compounds with which 2- that have in general physical properties superior vinyldibenzoiuran may be copolymerized are unto those obtained from a simple mixture of the saturated hydrocarbons, such as indene, aeep y e h e copolymers ny1d1- naphthylene,etc.; polymerizable oils; cyclopenta-- bBnZOfuran and Styrene are useful in y diene; and unsaturated alkyd resins. such as distances where styrene would be unsuitable due ethylene glycol maleate, etc. Such copolymers to its low softening point, but at the same time. yield compositions suitable for a large variety of the copolymers still possess electrical characterapplications. istics of the same order as polystyrene.

In carrying out these simultaneous polymer- The copolymerlzation products of the present izations, 2-vinyldibenzoiuran and compounds invention may vary in accordance with the na-' copolymerlzable therewith may be employed as ture and proportions of the copolymerizable such, in the presence of a diluent or solvent or compound which is copolymerized with the 2- in suspension or emulsion form. The polymerizavinyldibenzdfuran. For example, 2-vinyldibenzotion may be carried out in the presence or abfuran copolymerizes with butadiene to produce sence of a catalyst. The nature oi the products copolymers which vary from an elastic, flexible produced depends upon the conditions of poly- 40 material when the proportion of 2-vinyldibenzomeri'zation and the purity of the monomers em'- furan is high in the monomeric mixture to rubployed. In general, the purer the monomers the her-like masses when the butadiene component more readily and completely the polymerization is in high'proportion in the monomeric mixture. occurs. *In some cases where 2-vinyldibenzoiuran 2-vinyldibenzofuran can be cross-linked by copolymerizes with difllculty and to a small decompounds such as diviuyl, diallyl and diethylene gree. it will in the presence'of a third monomer glycol ester compounds to form products that readily form a copolymer or a mixed polymer of have increased heat resistance and can be readily the three monomers. machined and worked. Such products tend to- The polymerization may be accelerated or reward insolubility and iniusibility as the percent tarded so that products having vastly different of diviuyl compound increases. The'copolymers physical properties are formed. In general, it is of z-vinyldibenzoiuran with other vinyl comdesirable to choose conditions of polymerization pounds, with acrylic acid, acrylic, acid esters, and such that the monomers polymerize at about the unsaturated compounds are thermoplastic and same rate. If the rate of polymerization of one can be treated in general as any thermoplastic monomer is considerably greater than that of the as material. For example. they canbe injection or I Example 1 V 10.4 parts of styrene and 19.4 parts of 2-vinyldibenzofuran are heated for 24 hours at 80 C. in a closed vessel, then heated for 12 hours at 100 C. and for 12 hours at 125 C. A solid clear glassy polymeric mass is obtained which can be ground "up and mixed with a suitable filler. such as mica dust. silex. talc, e-oellulose. ground paper. asbestos, the metallic oxides, linen rags, etc.. to produce an excellent molding compound. If this solid mass is dissolved in benzene and precipitated with methyl alcohol so that any traces of monomeric material and the short chain length copolymer are removed, the resulting material will have a heat-distortion point in the neighborhood of 100 C. and produces clear pieces when injection or compression molded. It has a power factor of .04% in the range of 60 cycles to 1 megacycle and has a dielectric constant of 2.6.

Example 2 10.4 parts of styrene and 38.8 parts of 2-vinyldibhzofuran are heated in a closed vessel at 125 C. for24 hours. A hard, clear glassy mass is obtained of lower average molecular weight than produced in the preceding example. The above copolymer can be ground and mixed with a plasticizer such as tricresylphosphate, a eutectic mixture of diphenyl and diphenyl oxide, z-ethyldibenzofuran, dibutylphthalate, etc., to yield soft flexible masses which may be used as artificial leathers or water repellent compounds. For example, 100 parts of the above copolymer and 50 parts of 2-ethyldibenzofuran produce a mass which may be worked on rolls to form plastic sheets. The amount of plasticizer added may be varied within wide limits to produce compositions ranging from soft sticky masses to hard, tough resins.

Example 3 10.4 parts styrene and 77.6 parts of 2-vinyldibenzofuran are heated in a closed vessel at 65 C. for 96 hours. A hard, glassy polymeric mass is obtained which contains a copolymer of higher average molecular weight than that produced in Example 1. The heat-distortion point is higher than that of Example 1. This material when purified and plasticized with 25% of 2-ethyldibenzofuran produces films which possess excellent electrical characteristics.

Example 4 20.8 parts of styrene and 19.4 parts of 2-vinyldibenzofuran are heated in a closed vessel at 65 C. for 24 hours, then at 125 C. for 12 hours. A water-clear product is obtained.

Example 5 of water, amount and nature of the alkali may be varied within wide limits.

Instead of sodium peroxide, any inorganic or organic peroxide. the persulfates, the perborates, oxygen-supplying compounds, oxygen, air or ozone may be used.

Example 6.

104 parts of styrene, 194 parts of z-vinyldlbenzofuran. 300 parts of benzene are refluxed for 48 hours. The resulting viscous mixture is cooled,

104 parts of styrene and 194 parts of 2-vinyldibenzofuran are dissolved in 300 parts of trichlorethylene. The solution is cooled to 20 C. and the polymerization is started by the addition of some drops of the addition compound of BF: and diethylethcr. The reaction mass is constantly stirred and kept as near 20 C. as possible by cooling. After several hours, the polymerization is essentially completed and a white polymerized mass is precipitated with methyl alcohol. The proportions of styrene to 2-vinyldibenzoiuran may be varied at will.

The reaction may be carried out at higher temperatures but a copolymer of lower average molecular weight is obtained. At lower temperatures a product of much higher average molecular weight is obtained.

Instead of the addition compound of BF: and diethylether, SnCh, SbCls, H0], or AlCla may be used.

Example 8 To 194 parts of 2-vinyldibenzofuran and 104 194 parts of z-vinyldibenzofuran are fused with 193 parts of N-vinylcarbazole and heated at C. for 30 hours, then for 24 hours at 150 C. A

yellowish, hard polymerization mass is obtained which may be ground and used as a copolymer or compounded to form a molding compound or it may be dissolved in a suitable solvent and precipitated with a precipitant to remove the low molecular weight polymer and any unpolymerized monomer still present. This material has a high heat-distortion pointabout C. The proportions of N-vinylcarbazole to 2-vinyldibenzofuran may be varied at will. These two monomers may also be polymerized by any of the methods described in the foregoing examples, except that it is not necessary to use pressuretight vessels or reflux condensers on these two high boiling monomers. If 1% of a wax, such as Barnsdall wax, is added to the above polymeric mass, the resistance to moisture is improved. Such a copolymer has excellent electrical propstyrene.

Example 38.8 parts 2-vinyldibenzoiuran and 17.2 parts of vinyl acetate are heated at 100 C. for 48 hours. The resulting polymeric mass may be treated or worked in the same manner as any thermoplastic material. Simultaneous polymerizations 01' vinyl acetate and z-vinyldibenzoiuran may be carried out by any of the foregoing methods.

Example 11 0.83 part benzoyl peroxide,5.4 parts of butadiene, and 77.6 parts of 2-vinyldibenzofuran are heated at 100 C. for 24 hours in a pressuretight vessel, then for 24 hours at 125 C. The resulting solid polymeric mass is dissolved in benzene and precipitated with methyl alcohol. Films cast from this material show considerably more flexibility and durability than films from 100% polyvinyldibenzoiuran.

Example 12 Example 13 5.4 parts of butadiene, 19.3 parts of 2-vinyldibenzofuran, and .25 part of benzoyl peroxide were heated at 100 C. for 24 hours, then at 125 C. for 24 hours in a closed vessel. The resulting polymeric mass was still somewhat difiicultly soluble in benzene. The polymeric mass was precipitated with methyl alcohol. A film cast from this copolymer showed great flexibility a (the film can be folded upon itself without tearing) and unusual electrical properties, a power factor of .07% at one megacycle and a dielectric constant of 3.2. The film is transparent in thin sections, but is a bluish white tinge in thicker sections.

Example 14 10.8 parts butadiene, 19.4 parts 2-vinyldibenzofuran and 0.2, part benzoyl peroxide were heated to 100 C. for 24 hours in a closed, pressuretight vessel, then to 125 C. for 24 hours. In using larger amounts of butadiene, there is some small amount of butadiene left after the polymerization so the actual amount of butadiene in the copolymer is less than the amount indicated above. The above rubber-like polymerization mass shows evidence of insolubility, but is readily worked on rolls similar to the styrenebutadiene copolymers. Simultaneous polymerization of butadiene and 2-vinyldibenzofuran can also be carried out by any of the methods described in Examples 1 through 8.

Example 15- mixture or three Example 16 120 parts 2-vinyldibenzoiuran, parts of a parts styrene and 2 parts divinylbenzene are heated at 125C. for 48 hours. The resulting cross-linked polymerization mass can be readily machined and does not show signs of softening during the machining process.

Example 17 2 parts benzoyl peroxide. 194 parts of 2-vinyldlbenzofuran, and 20 parts of diallylphthalate were heated 24 hours at C. and 18 hours at C. in long test tubes. The resulting rods show no signs of softening at C. but show flexibility at this temperature.

Example 18 194 parts of z-vlnyldibenzofuran and 11 parts 01' divinyldibenzofuran were heated at 80 C. for 24 hours, at 100 C. for 24 hours, and at 125 C. for 12 hours. The resulting polymeric mass machines readily and possesses excellent electrical properties.

The copolymerizations described in Examples 15 through 18 can be carried out by any of the processes described in Examples 1 through 8 but since these cross-linked polymers are insoluble and infusible, it is usual to cast them in some predetermined form and polymerize them in place.

Example 19 38.8 parts of 2-vlnylclibenzofuran and 20 parts of methylmethacrylate were heated at 100 C. for 12 hours in a closed vessel. The polymerization mass was hard after 4 hours, but in order to carry the polymerization as far as possible the heating was continued until 12 hours Example 20 194 parts of 2-vinyldibenzofuran and 116 parts of indene were heated in a pressure-tight vessel at 125 C. for 48 hours. The solid polymeric mass obtained is of relatively short chain length. Polymer of high molecular weight is obtained if the polymerization is carried. out at lower temperatures. 2-vinyldibenzofuran and lndene may be simultaneously polymerized in all pro portions. Any of the methods described in Examples 1 through 8 may be used.

Example 21 98 parts of maleic anhydride, 194 parts of 2- vinyldibenzofuran, 3 parts of lauroyl peroxide, 300 parts of acetone and 200 parts of benzene are heated at 125 C. for 30 hours. A viscous liquid mixture is obtained from which the solid copolymerization mass may be precipitated by methyl alcohol. The proportion of maleic anhydride to 2-vinyldibenzofuran may be varied within wide limits. In place of benzoyl peroxide, any organic or inorganic peroxide, ozone, air, oxygen, or oxygen-liberating compounds may be used. The polymerization may be carried out mo re slowly in the absence of a catalyst. The choice of solvents will depend upon the relative amounts or maieic anhydride and 2-vinyldiasamas 7 bensoiuran that are present. The viscosity and hence the average molecular weight of the copolymer produced also depends upon the amount oi! catalyst used, the temperature and the proportions or the polymerizing substances.

Example 22 water mixtures.

Example 23 194 parts of 2-vinyldibenzoturan, 52 parts of polystyrene. and 3 parts of benzoyl peroxide are dissolved in 600 parts of benzene and heated at 100 C. in a closed vessel for 48 hours. The resulting polymer may be precipitated in the form of a white powder by methyl alcohol.

Example 24 56 parts of isobutylene, 194 partsof 2-vinyldibenzofuran, and 0.60 part of benzoyl peroxide are heated at 100 c. for 48 hours. The resulting polymeric mass may be precipitated from a dilute solution in the form of a white powder by methyl alcohol.

The preceding examples illustrate the preparation of copolymers wherein the 2-vinyldibenzoiuran comprises, by weight, from about 48 per cent to 91 per cent of the total weight 01 the copolymerizable ingredients. It will of course be understood that the applicant may employ larger or smaller proportions of the 2-vinyldibenzofuran without departing from the scope of his invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A composition comprising the product of polymerization of a mixture of difierent copolymerizable ingredients including 2-vinyldibenzofuran and a compound containing two CH2=C groupings, the 2-vinyldibenzofuran comprising,

8 by weight, from 48 to 91 per cent of the total weight of the copolymerizable ingredients.

2. The method or preparing a new synthetic composition which comprises polymerizing under heat and in the presence of a polymerization onto-- lyst. a mixture containing 19.3 parts by weight of 2-vinyldibenzoturan and 5.4 parts by weight of butadiene.

3. A copolymer of z-vinyldibenzoiuran and Imtadlene which isthe copolymerization product of 19.3 parts by weight oi. 2-vinyldibenzoiuran and 5.4 parts by weight 01' butadiene.

4. A composition oi matter comprising the product of polymerization of a mixture oi ingredients including 2-vinyldibenzofuran and styrene. the 2-vinyldibenzoiuran comprising irom about 48 to 91% 0! the total weight of the copolymerized ingredients.

5. A composition of matter comprising the prodnot of polymerization of a mixture of ingredients comprising z-vinyldibenzoiuran and butadiene. the z-vinyldibenzoiuran comprising from 48 to 91% ot the total weight oi the latter and the butadiene. e

6. A composition of matter comprising the product of polymerization of a mixture of ingredients comprising 2-vinyldibenzoi-uran and N- vinyl carbazole, the z-vinyldibenzoiuran comprising from 48 to 91% 01' the total weight of the latter and the N-vinyl carbazole.

'7. A composition comprising the product of polymerization of a mixture of diil'erent copolymerizable ingredients including 2-vinyldibenmfuran and a compound containing not more than two CH2=C groupings,'the 2-vinyldibenzoiuran comprising, by weight, from 48 to 91 per cent or :hetstotal weight ot-the' copolymerizable ingred- EDWARD A. KERN.

Country Date Great Britain June 22, 1945 Number 

1. A COMPOSITION COMPRISING THE PRODUCT OF POLYMERIZATION OF A MIXTURE OF DIFFERENT COPOLYMERIZABLE INGREDIENTS INCLUDING 2-VINYLDIBENZOFURAN AND A COMPOUND CONTAINING TWO CH2=C< GROUPINGS, THE 2-VINYLDIBENZOFURAN COMPRISING, BY WEIGHT, FROM 48 TO 91 PER CENT OF THE TOTAL WEIGHT OF THE COPOLYMERIZABLE INGREDIENTS. 